Gastric cancer in San Marinese and their first degree relatives in San Marino and the United States. Gastroscopic biopsy as an epidemiological tool.

The Republic of San Marino, a small, 23-square mile, independent country near the Adriatic Coast within Italy, has been noted to have a high incidence of gastric cancer in its 22,000 population (9% of all deaths from 1969-1983 with 33% of all cancer deaths attributed to gastric cancer). Gastroscopic biopsy studies on 284 first degree relatives of San Marinese gastric cancer patients in the Republic of San Marino and in Detroit, where 2,000-2,500 San Marinese reside, have allowed detection of six gastric malignancies. Intestinal metaplasia of gastric mucosa was found in 16 (52%) of 31 Detroit first degree relatives and 51 (36%) of 143 San Marino first degree relatives. Gastroscopy provides an important tool not only for the early detection of gastric cancer in populations of high risk (such as that of San Marino), but also for providing clues to the genetic and environmental factors in gastric neoplasia.